JP2014000630A - Coolant supply mechanism in cutting tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a cap member in which a female screw engaged with a coolant supply connector is formed, to be mounted on a mounting hole without loosening or detaching.SOLUTION: Coolant holes 10 are formed at positions eccentric from a center line O of a mounting hole 9 formed in a shank portion 2 on a rear end of a tool main body 1, and a cap member 11 of a cylindrical external shape is fitted and inserted into the mounting hole 9. A coolant supply path 12 opening in the mounting hole 9 and communicating with the coolant holes 10 of the tool main body 1, and a female screw 11a communicating with the coolant supply path 12 and opening coaxially with the center line O in a rear end of the cap member 11 exposed to an opening of the mounting hole 9 are formed on the cap member 11. The cap member 11 is detachably mounted on the mounting hole 9 via whirl-stop members 14, and the whirl-stop members 14 are provided at positions avoiding openings of the coolant holes 10 and eccentric from the center line O.

Description

  The present invention relates to a coolant supply mechanism in a cutting tool for supplying coolant to a cutting part of a cutting edge or a work material in a cutting tool such as a drill or a boring bar.

  In cutting with a cutting tool, cooling against cutting heat generated at the cutting edge of the cutting edge and the cutting part of the work material, lubrication of the cutting edge and cutting part, or chips generated from the cutting part of the work material by the cutting edge Supply of coolant such as cutting fluid is indispensable for improving the discharge efficiency. In particular, in cutting with a drilling tool such as a drill or boring bar, the cutting part of the work material becomes the bottom surface of the drilled hole or the inner peripheral surface of the prepared hole, so that the cutting heat is easily trapped or clogged with chips. On the other hand, even if it is attempted to supply the coolant from the outside of the tool body of the cutting tool, it is difficult to reliably and efficiently supply the coolant to the cutting site.

  Therefore, for example, in Patent Document 1, a coolant hole is formed in the land portion of the drill body front end portion and the front end thereof is opened in the vicinity of the cutting blade, and the rear end of the coolant hole is a shank of the drill body rear end portion. Open in the mounting holes formed on the rear end face of the unit, and install the retainer in which the female thread part to which the connector of the hose to which the coolant is supplied is connected is formed in this mounting hole. In addition, a coolant supply mechanism has been proposed in which coolant is supplied to a cutting edge or a cutting site of a work material through a coolant hole.

  In such a coolant supply mechanism, since the coolant hole is formed inside the drill body, the cutting edge and the cutting part of the work material are reliably and efficiently cut off by the work material and generated chips. Coolant can be supplied to In addition, since the coolant hole is formed in the land portion between the chip discharge grooves at the tip of the drill body in particular, the core thickness should be reduced as compared to, for example, forming the coolant hole along the center axis of the drill body. Conversely, since the cross-sectional area of the chip discharge groove can be increased, the chip discharge performance can be improved.

JP 2009-142984 A

  However, in the coolant supply mechanism described in Patent Document 1, the cage in which the female screw portion is formed is fixedly attached to the mounting hole of the drill body by means such as adhesion or shrink fitting, When the retainer is damaged due to the screw thread of the female thread portion being crushed or the like, it is not easy to replace only the retainer. In some cases, the entire drill body must be discarded. In addition, it is difficult to secure sufficient mounting strength when the cage is attached by bonding, and when attaching the cage by shrink fitting, heating means is required to heat the drill body and expand the mounting hole. In addition, since the drill body is distorted by heating, it is necessary to finish the drill body after the retainer is attached.

  Here, in order to solve such a problem, it is conceivable that the retainer can be attached to and detached from the drill body, and screwing is generally considered as an attaching / detaching means for making the retainer attachable / detachable. However, a female screw portion is simply formed on the inner peripheral surface of the mounting hole, and a male screw portion is formed on the outer peripheral surface of the cage to be screwed with the female screw portion, or is fixed with screws, or is inserted into the cage. When screwing into the screw hole formed on the bottom surface of the mounting hole and screwing, the male screw part on the outer peripheral surface of the connector for the coolant supply hose is screwed into the female screw part on the inner peripheral surface of the cage. Or, when the male screw part is loosened and the connector is removed, the cage may rotate together with the connector and loosen or come off the mounting hole.

  On the other hand, it is conceivable to directly form a female threaded part that engages with the male threaded part of the connector on the rear end face of the shank part of the drill body. The main body must be discarded. Moreover, when the coolant hole is formed in the land portion of the tip end portion of the drill body as in the coolant supply mechanism described in Patent Document 1, and is eccentric from the center line of the drill body, the shank portion, and the mounting hole, the female screw portion Since the inner diameter of each is constant according to the male thread part of the connected connector for supplying coolant, the coolant hole cannot be reliably opened to a position other than the part where the female thread part of the mounting hole is formed. In some cases, the coolant hole may overlap the internal thread portion, resulting in coolant leakage.

  The present invention has been made under such a background, and when the coolant hole is eccentric from the center line of the mounting hole as described above, the female threadedly engaged with the male screw portion of the connector for supplying coolant is provided. It is an object of the present invention to provide a coolant supply mechanism in a cutting tool in which a threaded portion is formed in a cap member that can be detachably attached to an attachment hole, and the cap member can be attached to the attachment hole without loosening or coming off.

  In order to solve the above problems and achieve such an object, the present invention provides a cutting method in which coolant is supplied to a coolant hole extending from a shank portion at a rear end portion of a tool body of a cutting tool toward the tip portion of the tool body. A coolant supply mechanism in a tool, wherein a mounting hole is formed in the shank portion, and the coolant hole is opened at a position deviated from a center line of the mounting hole. The cap member has a coolant supply passage and a female screw portion formed in the cap member. The coolant supply passage opens into the mounting hole and communicates with the coolant hole. A portion that communicates with the coolant supply path and that is open coaxially with the center line on the rear end surface of the cap member exposed at the opening of the mounting hole. Is attached detachably to the mounting hole via a detent member, and the detent member is arranged at a position eccentric from the center line avoiding the opening of the coolant hole. To do.

  In the coolant supply mechanism configured as described above, the coolant hole is opened in the mounting hole formed in the shank portion at the rear end portion of the tool body, and is screwed with the male screw portion of the connector for supplying coolant. A cap member in which a female screw portion is formed is fitted into the mounting hole. For this reason, even if the coolant hole is eccentric from the center line of the mounting hole, shank, or tool body, the coolant hole can be securely inserted into the mounting hole by appropriately setting the inner and outer diameters of the mounting hole and the outer cylindrical cap member. And can be communicated with the female thread portion connected to the connector via the coolant supply passage of the cap member.

  And this cap member is detachably attached to a mounting hole that is inserted and inserted via a detent member disposed at a position eccentric from the center line of the mounting hole, similar to the coolant hole. Even if it is coaxial with the center line of the mounting hole, it is possible to prevent the cap member from rotating together and loosening or coming off the mounting hole when connecting or removing the connector. In addition, since the cap member is detachable, even if damage occurs, only the cap member can be replaced, and it is not necessary to discard the entire tool body, and no distortion due to heat occurs in the tool body. There is no need for final finishing after the cap member is attached.

  Here, in order to detachably attach the cap member to the attachment hole via the rotation preventing member eccentric from the center line, a through hole is formed from the bottom surface of the female screw portion to the tip surface of the cap member, The cap member is detachably attached to the mounting hole with a mounting screw having a screw shaft portion inserted into the through hole and a head having an outer diameter larger than the inner diameter of the through hole. It is easy to use a non-rotating pin that can be fitted in a fitting hole formed at a position eccentric from the center line on the tip surface and the bottom surface of the mounting hole. In this case, the through hole is coaxial with the center line. Even if the cap member is formed, the rotation of the cap member can be prevented by the rotation prevention pin.

  However, in order to prevent the cap member from rotating together with the non-rotating pin in this way, in order to make the cap member detachable, a slight clearance is required between the non-rotating pin and the fitting hole. Even if it can be prevented, there is a risk that the cap member will rattle. In particular, when the through hole is formed so as to be coaxial with the center line of the mounting hole as described above, the outer diameter of the shank portion is small, and the inner and outer diameters of the mounting hole and the cap member must be reduced. In such a case, the inner and outer diameters of the fitting hole and the non-rotating pin are inevitably small, and there is a possibility that sufficient strength against the detent cannot be secured.

  Therefore, the mounting screw itself, which has a head portion and a screw shaft portion and is detachably attached to the mounting hole, is used as a non-rotating member, so that the head portion presses the cap member without clearance by screwing the screw shaft portion. Can be attached to prevent rattling. In addition, since the mounting screw itself is a non-rotating member and is arranged at a position eccentric from the center line, that is, screwed in, the outer diameter of the shank portion is small, and the inner diameter of the mounting hole and the cap member is also small. Even if it must be reduced, the outer diameter of the screw shaft portion and the head of the mounting screw can be secured relatively large, and the strength against rotation can be sufficiently secured.

  By the way, when screwing into the position eccentric from the center line of the mounting hole as a mounting screw in this way, if the inner diameter of the female screw part is sufficiently large, as in the case of using the locking pin as a rotation preventing member, A through hole penetrating from the bottom surface of the female screw portion to the tip surface of the cap member is formed at a position eccentric from the center line, and the screw shaft portion of the mounting screw is inserted into the through hole through the inner periphery of the female screw portion. By engaging and rotating a work tool such as a wrench in the engaging portion formed on the head, the screw shaft portion is screwed into the screw hole formed on the bottom surface of the mounting hole to attach the cap member and prevent rotation. be able to.

  However, as described above, the inner diameter of the female screw portion is constant according to the male screw portion of the connector for supplying coolant to be connected, and therefore, through the inner periphery of the female screw portion that is coaxial with the center line of the mounting hole, Depending on the amount of eccentricity from the center line of the through hole, even if you try to insert the mounting screw including the head so that the screw shaft is inserted into the through hole formed at a position eccentric from this center line, Otherwise, the screw shaft portion may interfere with the female screw portion and the mounting screw may not be inserted.

  Therefore, in order to screw the mounting screw into a position that is eccentric from the center line of the mounting hole while preventing such interference with the female thread portion, the distal end surface and the outer periphery of the cap member are located closer to the distal end side than the female thread portion of the cap member. A slit having an inner peripheral end is formed at a position away from the center line while opening in the surface and extending to the inner peripheral side, and the tip end portion of the slit is larger than the diameter of the screw shaft portion and is larger than the head portion. The screw shaft is inserted into the slit tip so that the slit width is small and the rear end of the slit is wider than the head and the inner peripheral end is opened at the bottom of the female screw. The head is inserted into the rear end of the slit and the mounting screw is disposed at the inner peripheral end, and the engaging portion formed at the head is disposed on the inner peripheral end. Work from the opening on the bottom May be such that the tool and engageable.

  With this configuration, the mounting screw is inserted from the outer periphery of the cap member into the slit formed on the tip side of the female screw portion of the cap member without interfering with the female screw portion, and is eccentric from the center line. In the state where the slit is located at the inner peripheral end of the slit in this manner, the engaging screw of the mounting screw head exposed to the bottom opening through the inner periphery of the female screw part can be used for work. The mounting screw is rotated by engaging the tool, the screw shaft is screwed into the screw hole formed at the position corresponding to the inner peripheral end of the bottom surface of the mounting hole, and the cap member is detachably attached to the mounting hole. Can do.

  If a plurality of slits are formed in the cap member at equal intervals in the circumferential direction and a mounting screw is inserted and screwed into each of these slits, the mounting strength of the cap member and the strength against rotation can be improved. be able to. Further, even when the mounting screw itself is used as a non-rotating member, or when the non-rotating pin is used as a non-rotating member as described above, the rear end of the cap member in the mounting hole is behind the opening of the coolant supply path. On the side, if a seal member is interposed between the inner peripheral surface of the mounting hole and the outer peripheral surface of the cap member, leakage of the coolant can be prevented more reliably.

  As described above, according to the present invention, by attaching the cap member to the attachment hole in a detachable manner, only the cap member can be replaced even when the female screw portion is damaged, and the entire tool body is discarded. There is no need to prevent the cap member from loosening or coming out of the mounting hole even when a connector for supplying coolant is connected to or removed from the female thread. Can do.

(A) Side view, (b) Rear view, (c) CC cross-sectional view in Fig. (B), (d) DD cross-section in Fig. (B) showing a first embodiment when the present invention is applied to a drill FIG. (A) side view, (b) rear view, (c) CC sectional view in FIG. (B), (d) DD sectional view in FIG. It is EE sectional drawing in (a). 1A is a front view of the cap member in the embodiment shown in FIG. 1, FIG. 1B is a partially broken side view in the direction of arrow B in FIG. 1A, and FIG. 1C is in the direction of arrow C in FIG. It is a partially broken side view, (d) Rear view, (e) It is EE sectional drawing in FIG. (C). FIG. 3A is a front view showing a modification of the cap member shown in FIG. 3, FIG. 3B is a partially broken side view of FIG. 3A viewed in the direction of arrow B, and FIG. 3C is viewed in the direction of arrow C in FIG. It is a partially broken side view, (d) Rear view, (e) It is EE sectional drawing in FIG. (C). (A) Side view, (b) Rear view, (c) CC sectional view in Fig. (B), (d) DD section in Fig. (B) showing a second embodiment when the present invention is applied to a drill FIG. (A) side view, (b) rear view, (c) CC sectional view in FIG. 5 (b), (d) DD sectional view in FIG. It is EE sectional drawing in (a). 5A is a front view of the cap member in the embodiment shown in FIG. 5, FIG. 5B is a partially broken side view in the direction of arrow B in FIG. 5A, and FIG. 5C is in the direction of arrow C in FIG. It is a partially broken side view, and (d) is a rear view. (A) Side view, (b) Rear view, (c) CC sectional view in Fig. (B), (d) DD in Fig. (B) showing a third embodiment when the present invention is applied to a boring bar. It is sectional drawing.

  1 to 3 show a first embodiment in the case where the present invention is applied to a blade-replaceable drill. A drill main body 1 as a tool main body of a cutting tool in the present embodiment is formed of a metal material such as a steel material, and has an outer shape with a multistage substantially cylindrical shape centering on a center line O as shown in FIGS. In addition, the rear end portion in the longitudinal direction (the right side portion in FIG. 1A) is the outer cylindrical column shank portion 2, and the front end side of this shank portion 2 (the left side in FIG. 1A) is one step. A disc-shaped flange portion 3 having a maximum outer diameter is formed through a portion that is slightly reduced in diameter, and a cutting edge portion 4 having an outer cylindrical shape is formed again on the distal end side of the flange portion 3. . A notch surface 2 a substantially parallel to the center line O is formed on the outer peripheral surface of the shank portion 2.

  In such a drill, usually, the shank portion 2 is gripped by the main shaft of the machine tool and rotated around the center line O in the drill rotation direction T shown in FIG. Then, the work material is drilled with a cutting blade provided at the tip of the cutting blade portion 4. However, conversely, the shank portion 2 is held on the tool post and the drill body 1 is fixed, the work material is rotated around the center line O in the direction opposite to the drill rotation direction T, and the tool post is rotated. In some cases, drilling is performed on the work material by feeding the drill body 1 toward the front end side in the center line O direction.

  On the outer periphery of the cutting edge portion 4, a pair of twists about the center line O toward the rear side in the drill rotation direction T toward the rear end side from the tip end of the cutting edge portion 4 to the tip surface of the truncated cone shape of the flange portion 3. Spiral chip discharge grooves 5 are formed at equal intervals in the circumferential direction, and a portion between these chip discharge grooves 5 is a pair of land portions 6. In addition, an insert mounting seat 7 is formed at the tip of the wall surface of each chip discharge groove 5 facing the drill rotation direction T, and a cutting insert 8 formed of a hard material such as cemented carbide is attached. The cutting blade is formed on the cutting insert 8.

  A mounting hole 9 is formed in the shank portion 2 from the rear end surface toward the front end side. The mounting hole 9 has a circular shape with a constant inner diameter centered on the center line O, and is formed from the rear end surface of the shank portion 2 to the front of the central portion in the longitudinal direction of the shank portion 2, and the bottom surface of the hole is the center. It is perpendicular to the line O. Further, as shown in FIG. 2B, a plurality (two in this embodiment) of mounting screw holes 9a are located near the inner periphery of the bottom surface of the hole, but at a position eccentric from the center line O of the mounting hole 9. Are formed symmetrically with respect to the center line O, that is, at equal intervals in the circumferential direction and perpendicular to the bottom surface of the hole.

  Further, a pair of coolant holes 10 are drilled from the bottom surface of the mounting hole 9 toward the distal end side of the drill body 1. These coolant holes 10 are also opened eccentrically from the center line O at positions near the outer periphery of the bottom surface of the mounting hole 10 as shown in FIG. In this way, it extends linearly to the distal end side, passes through the pair of lands 6 of the cutting edge portion 4 from the flange portion 3, and is opened, for example, on the distal end surface (distal flank surface) of the drill body 1. . In addition, in the rear view of the tool body 1, the straight line connecting the centers of the pair of coolant holes 10 and the straight line connecting the centers of the two mounting screw holes 9a are perpendicular to each other as shown in FIG. It is designed to intersect at close angles.

  A flat cutout surface 3 a parallel to the center line O is formed on the outer peripheral surface of the flange portion 3, and a blind hole-shaped coolant communication hole 10 a is drilled perpendicularly to the centerline O from the cutout surface 3 a. It is installed. This coolant communication hole 10a has a larger inner diameter than each coolant hole 10 and a smaller inner diameter than the mounting hole 9, and the pair of coolant holes in the flange 3 as shown in FIG. 10 is crossed and communicated. A female threaded portion 10b is formed at the opening of the coolant communication hole 10a to the cutout surface 3a. The female threaded portion 10b has the same diameter as the female threaded portion 11a of the cap member 11 described below and has an inner peripheral side. The taper screw gradually decreases in diameter as it goes to.

  A cap member 11 having an outer cylindrical shape as shown in FIG. 3 is fitted into the mounting hole 9 so as to be coaxial with the center line O. The cap member 11 is also formed of a metal material such as steel like the drill main body 1, and the female screw portion of the coolant communication hole 10 a is formed from the rear end surface (the surface facing the right side in FIGS. 3B and 3C). The cap member 11 has the same diameter as 10b and a taper screw-like female thread portion 11a that gradually decreases in diameter toward the distal end side (left side in FIGS. 3B and 3C). Are formed up to substantially the central part in the longitudinal direction (the left-right direction in FIGS. 3B and 3C). An annular groove 11b having a U-shaped cross section is formed on the outer peripheral surface of the rear end portion of the cap member 11 in which the female screw portion 11a is formed.

  Further, a coolant supply path 12 is formed on the tip side of the cap member 11 with respect to the female screw portion 11 a, and the female screw portion 11 a is communicated with the coolant supply path 12. The coolant supply path 12 includes a vertical hole portion 12a extending from the screw hole bottom surface of the female screw portion 11a to the distal end side, a horizontal hole portion 12b extending across the vertical hole portion 12a and extending to the outer peripheral side of the cap member 11, and the horizontal hole portion 12b. The outer peripheral side opening of the cap member 11 is formed by a notch 12c formed so as to cut out the outer peripheral surface of the cap member 11.

  The vertical hole portion 12a is a circular hole centered on a center line O having a constant inner diameter that is slightly smaller than the inner diameter of the screw hole bottom surface of the female screw portion 11a. However, the hole bottom portion has a concave conical surface. The horizontal hole portion 12b is a circular hole having a smaller diameter than the vertical hole portion 12a and extends in a direction perpendicular to the center line O. Are opened in the opposite direction in the circumferential direction. Further, the notch portion 12c is formed so that the outer peripheral surface of the cap member 11 is cut out by a plane perpendicular to each of the horizontal hole portions 12b at the outer peripheral side opening portions of the pair of horizontal hole portions 12b. Is formed so as to be recessed in parallel to the inner circumferential side of the first stage from the vertical plane.

  In addition, a slit 13 is formed on the distal end side of the cap member 11 with respect to the female screw portion 11a, and is open to the distal end surface and the outer peripheral surface of the cap member 11 and extends to the inner peripheral side. In the present embodiment, the same number of (two) slits 13 as the mounting screw holes 9a formed on the bottom surface of the mounting hole 9 are formed at equal intervals in the circumferential direction so as to be symmetrical with respect to the center line O. Yes. As shown in FIG. 3 (b), these slits 13 have a T-shaped cross section in which the front end portion 13a is narrower by one step than the rear end portion 13b. 3 (a), (b), (d), and (e), the plane located at the center in the vertical direction) includes the center line O, and extends in a direction orthogonal to the center line of the lateral hole 12b of the coolant supply passage 12. Has been.

  The slit width of the tip 13a of the slit 13 is slightly larger than the inner diameter of the mounting screw hole 9a. The rear end surface of the rear end portion 13b of the slit 13 is flush with the screw hole bottom surface of the female screw portion 11a in the center line O direction (longitudinal direction). The hole bottom portion having a concave conical surface in the vertical hole portion 12 a is partially cut out by the slit 13.

  Further, the slit 13 is disposed at a position where the inner peripheral end 13 c does not reach the center line O and is separated from the center line O toward the outer peripheral side. Here, in the slit 13 in the present embodiment, the front end portion 13a and the rear end portion 13b have a constant slit width in the portion extending from the outer peripheral surface of the cap member 11 to the inner peripheral side, and the center line O of the inner peripheral portion. In the vicinity, as shown in FIG. 3 (e), a cross section perpendicular to the center line O is formed in a concentric semicircular arc shape that is concave on the inner peripheral side with the slit width of the front end portion 13a and the rear end portion 13b as a diameter. The center of this semicircular arc is the inner peripheral end 13 c of the slit 13.

  Therefore, in the present embodiment, the thickness of the tip portion of the cap member 11 is left on the center line O between the tip portions 13 a of the plurality of slits 13. In this embodiment, the rear end portion 13b of the slit 13 is overlapped by the plurality of slits 13, so that the thickness of the cap member 11 is not left in this portion. Further, the step surface between the front end portion 13 a and the rear end portion 13 b of the slit 13 is a flat surface perpendicular to the center line O. Further, the distance between the centers of the two attachment screw holes 9 a formed on the bottom surface of the attachment hole 9 is substantially equal to the distance between the inner peripheral ends 13 c of these slits 13.

  Such a cap member 11 is detachably attached to the attachment hole 9 with an attachment screw 14 having a head portion 14a and a screw shaft portion 14b. In the present embodiment, the same number of mounting screws 14 as the slits 13 are used. The slit width of the front end portion 13a of the slit 13 is slightly larger than the outer diameter of the screw shaft portion 14b of the mounting screw 14, and the slit width of the rear end portion 13b is larger than the outer diameter of the screw shaft portion 14b. It is smaller than the outer diameter. Furthermore, a hexagonal hole-like engaging portion 14c that engages with a hexagon wrench that is a work tool is formed on the rear end surface of the head portion 14a, and the back surface of the head portion 14a is a plane perpendicular to the center line of the mounting screw 14. The screw shaft portion 14 b can be screwed into the mounting screw hole 9 a of the mounting hole 9.

  The mounting screw 14 is inserted into the slit 13 from the outer peripheral side of the cap member 11 with the screw shaft portion 14b inserted into the front end portion 13a of the slit 13 and the head portion 14a inserted into the rear end portion 13b. When the line substantially coincides with the inner peripheral end 13c of the slit 13, it is disposed at the inner peripheral end 13c. With the mounting screw 14 thus arranged at the inner peripheral end 13c of the slit 13, the engaging portion 14c formed on the head portion 14a is formed into the female screw portion 11a of the cap member 11 as shown in FIG. So as to be exposed from the vertical hole portion 12a of the coolant supply passage 12 opened in the bottom surface of the screw hole, that is, the entire engaging portion 14c is positioned in the vertical hole portion 12a in the rear view of the cap member 11, and is engaged. The part 14c can be engaged with a hexagon wrench as a work tool.

  Thus, the cap member 11 in which the mounting screw 14 is inserted into each slit 13 is formed in the mounting hole 9 so that the inner peripheral end 13c of the slit 13 coincides with the center of the mounting screw hole 9a in the rear view of the drill body 1. Inserted. At this time, a seal member 15 such as an O-ring is accommodated in the annular groove 11 b on the outer peripheral surface of the cap member 11, and is interposed between the outer peripheral surface of the cap member 11 and the inner peripheral surface of the mounting hole 9. Further, since the engaging portion 14c of the mounting screw 14 is exposed in the vertical hole portion 12a of the coolant supply path 12, a hexagonal wrench as a work tool is inserted from the female screw portion 11a through the vertical hole portion 12a to engage. When the attachment screw 14 is rotated by engaging with the portion 14 c, the screw shaft portion 14 b is screwed into the attachment screw hole 9 a and the cap member 11 is detachably attached to the attachment hole 9.

  At this time, the pair of coolant holes 10 are located near the outer periphery on the bottom surface of the mounting hole 9 so that the straight line connecting the centers thereof and the straight line connecting the centers of the two mounting screw holes 9a intersect at an angle close to vertical. In addition, the slit 13 through which the mounting screw 14 is inserted in the cap member 11 extends in a direction perpendicular to the center line of the lateral hole portion 12b of the coolant supply path 12, so that the plane perpendicular to the lateral hole portion 12b The cutout portion 12 c of the coolant supply path 12 formed by cutting out the outer peripheral surface of the cap member 11 is communicated with the coolant hole 10.

  In order to supply the coolant through the coolant supply path 12 of the cap member 11 when drilling the work material using the drill with the cap member 11 attached in this manner, a two-dot chain line in FIG. As shown in FIG. 4, a hose connector for supplying coolant connected to the coolant supply means on the machine tool side or a male screw portion which is a taper screw on the outer periphery of the tube joint C is screwed into the female screw portion 11a of the cap member 11. Together, the connector or tube joint C is connected to the cap member 11, and the coolant communication hole 10a of the flange 3 is sealed by screwing a sealing screw 16 into the female screw portion 10b. FIG. 1A shows a case where drilling is performed by fixing the drill body 1 to the tool rest and rotating the work material as described above.

  Thus, when the connector or the tube joint C is connected to the female threaded portion 11a of the cap member 11 and the coolant is supplied, the coolant is transferred from the vertical hole portion 12a of the coolant supply path 12 opened to the bottom surface of the female threaded portion 11a to the horizontal hole. It flows into the portion 12b and is then supplied to the coolant hole 10 through the gap between the notch portion 12c and the mounting hole 9. Further, the coolant thus supplied to the coolant hole 10 passes through the coolant communication hole 10a in the flange portion 3 and passes through the land portion 6 of the cutting blade portion 4 and is then ejected from the tip of the drill body 1 to cut the cutting blade and the workpiece. Supplied to the cutting site of the material.

  Therefore, according to the cutting tool (drill) provided with the coolant supply mechanism having the above-described configuration, the coolant can be directly supplied from the inside of the tool main body (drill main body 1) to the cutting portion of the cutting blade or the work material. As a result, reliable and efficient cooling and lubrication can be achieved, and the discharge of chips generated by the cutting blade can be improved. In particular, in the drill of this embodiment, the coolant hole 10 is formed in the land 6 portion of the cutting edge portion 4, and the center line portion of the drill body 1 in the cutting edge portion 4, that is, the portion on the center line O of the mounting hole 9. Is solid, it is possible to reduce the diameter of the core thick circle in contact with the bottom surface of the chip discharge groove 5 around the center line O in the cross section orthogonal to the center line O, and conversely the chip discharge groove 5 Since a large cross-sectional area can be secured, it is possible to further improve the chip discharging property.

  Even when the coolant hole 10 extends to a position eccentric from the center line O as it passes through the land portion 6 in this way, the coolant hole 10 is formed in the large-diameter mounting hole 9 formed in the shank portion 2. And a coolant supply passage 12 that opens to the attachment hole 9 and communicates with the coolant hole 10, and a connection that communicates with the coolant supply passage 12 and is coupled to the coolant supply means. Since the cap member 11 having the internal thread portion 11a to which the vessel or the tube joint C is connected is attached, the coolant can be reliably supplied from the attachment hole 9 to the coolant hole 10 via the cap member 11. it can.

  Furthermore, since the cap member 11 is detachably attached to the attachment hole 9, only the cap member 11 needs to be replaced when the screw thread of the female screw portion 11a is damaged, for example, which is efficient and economical. is there. Further, since it is not necessary to heat the tool body (drill body 1) as in the case of mounting by shrink fitting, it is not necessary to apply a final finishing process to the drill body 1 in order to correct distortion after heating.

  In this embodiment, the cap member 11 is detachably attached to the attachment hole 9 by the attachment screw 14, and the attachment screw 14 is arranged at a position eccentric from the center line O of the attachment hole 9. Since the anti-rotation member in this embodiment is used, when connecting the connector or tube joint C to the female screw portion 11a, or when removing the connector or tube joint C from the female screw portion 11a, the cap member 11 is It does not loosen and rotate out of the mounting hole 9 together. For this reason, the coolant is supplied while the cap member 11 is loosened to cause a coolant leakage, and the trouble of reattaching the cap member 11 that has been detached from the attachment hole 9 does not occur, and smooth cutting is performed. be able to.

  Further, in the present embodiment, the mounting screw 14 that removably attaches the cap member 11 to the mounting hole 9 is used as a non-rotating member, and the screw shaft portion 14b of the mounting screw 14 is screwed into the mounting screw hole 9a. As a result, the back surface of the head portion 14a presses the step surface between the front and rear end portions 13a and 13b of the slit 13, whereby the cap member 11 can be stably attached without rattling.

  Further, since the cap member 11 is prevented from rotating and fixed by the mounting screw 14 screwed into the position eccentric from the center line O in this way, another mounting screw for fixing the cap member 11 is provided on the center line O. There is no need. Accordingly, since interference with other mounting screws does not occur, the outer diameter of the head 14a and the screw shaft portion 14b of the mounting screw 14 can be made relatively large, and the mounting strength of the cap member 11 can be increased. It becomes possible to ensure sufficient anti-rotation strength.

  Furthermore, in the present embodiment, in order to dispose the mounting screw 14 as a non-rotating member at a position eccentric from the center line O in this way, the distal end portion 13a is located closer to the distal end than the female thread portion 11a of the cap member 11. The slit 13 having a slit width larger than the diameter of the screw shaft portion 14b and smaller than the diameter of the head portion 14a and the slit width of the rear end portion 13b larger than the diameter of the head portion 14a is connected to the tip of the cap member 11. It is formed so as to have an inner peripheral end 13c at a position away from the center line O, and an attachment screw 14 is inserted into the slit 13 from the outer peripheral side. .

  However, if the inner diameters of the female screw portion 11a of the cap member 11 and the vertical hole portion 12a of the coolant supply path 12 can be sufficiently increased, the center line extends from the hole bottom of the vertical hole portion 12a to the front end surface of the cap member 11. Although a through hole is formed at a position eccentric from O, the screw shaft portion 14b can be inserted into the through hole, and the head 14a can be accommodated in the vertical hole portion 12a, and the mounting screw 14 can be screwed into the mounting screw hole 9a. The size of the female screw portion 11a is determined by the connector of the coolant supply means on the machine tool side or the male screw portion of the tube joint C, and cannot be made larger than this. For this reason, if it is going to increase the eccentricity of the said through hole in order to raise the intensity | strength with respect to a rotation stopper, the head 14a and the screw shaft part 14b will interfere with the internal thread part 11a, and will insert the attachment screw 14 in a through hole. Will not be able to.

  On the other hand, in the present embodiment, the mounting screw 14 is inserted into the slit 13 from the outer peripheral side and disposed at the inner peripheral end 13c eccentric from the center line O, and thus is disposed at the inner peripheral end 13c. The engaging hole 14c formed in the head 14a of the mounting screw 14 is exposed from the opening of the vertical hole 12a on the bottom surface of the female screw 11a, and the working tool is inserted and engaged through this opening. If it is possible, even if the outer periphery of the head 14a protrudes from the opening as shown in FIG. 1B and is hidden, the mounting screw 14 can be rotated and screwed into the mounting screw hole 9a. For this reason, according to this embodiment, it is possible to screw the attachment screw 14 as a rotation prevention member into the attachment screw hole 9a at a position further away from the center line O, and to improve the rotation prevention strength. .

  Furthermore, in the present embodiment, a plurality (two) of such slits 13 are formed in the cap member 11, and mounting screws 14 are inserted into the slits 13 and screwed into the mounting screw holes 9a. Therefore, the cap member 11 can be securely and more firmly attached and can be prevented from rotating. Moreover, since these slits 13 are formed at equal intervals in the circumferential direction of the cap member 11, the cap member 11 can be stably attached and prevented from rotating, and the mounting screws 14 interfere with each other. Can also be prevented.

  However, in the present embodiment, the plurality of slits 13 are formed at equal intervals in the circumferential direction of the cap member 11 as described above, but, for example, like the cap member 21 of the modification of the first embodiment shown in FIG. In addition, only one slit 13 may be formed by disposing the inner peripheral end 13c at a position eccentric from the center line O. Note that, in this modified example as well, in the second and third embodiments to be described later, the same reference numerals are assigned to portions common to the first embodiment, and description thereof is omitted.

  Even in the coolant supply mechanism in the cutting tool using the cap member 21 of such a modification, the cap member 21 is attached to the mounting hole 9 of the drill body 1 by one mounting screw 14 disposed at a position eccentric from the center line O. Can be attached and locked. In this case, the mounting hole 9 may have only one mounting screw hole 9a. Furthermore, since interference with other mounting screws 14 does not occur, for example, the diameter of the head 14a may be made larger than that of the first embodiment, and the cap member 21 may be mounted more firmly.

  Next, FIG. 5 thru | or FIG. 7 shows 2nd Embodiment at the time of applying this invention to a drill. In the present embodiment, the mounting screw hole 9a is not a position eccentric from the center line O of the mounting hole 9 as in the first embodiment, but only one is formed on the center line O. The slits 13 are not formed in the member 31, but a through hole 32 that is a stepped hole is formed along the center line O from the hole bottom of the vertical hole portion 12 a of the coolant supply path 12 to the tip surface of the cap member 31. ing.

  On the other hand, on the front end surface of the cap member 31 and the bottom surface of the mounting hole 9, fitting holes 33 and 34 having substantially the same inner diameter at positions eccentric from the center line O by the same amount of eccentricity avoiding the opening of the coolant hole 10. 7 is formed, and a detent pin 35 as a detent member in this embodiment is fitted in the fitting hole 33 of the cap member 31 as shown in FIG. As shown in FIG. 7A, the fitting hole 33 of the cap member 31 is centered on a plane that includes the center line O and is orthogonal to the center line of the lateral hole portion 12b of the coolant supply path 12. As shown in FIG. 6B, the fitting hole 34 of the mounting surface 9 is substantially the same as the straight line connecting the center of the fitting hole 34 and the center line O and connecting the openings of the pair of coolant holes 10. It is designed to be positioned in the orthogonal direction.

  In such a second embodiment, the cap member 31 is fitted into the mounting hole 9 so that the detent pin 35 fitted in the fitting hole 33 is fitted in the fitting hole 34, The mounting screw 36 inserted through the through hole 32 is screwed into the mounting screw hole 9a so as to be detachably attached to the mounting hole 9. In this case as well, the rotation of the cap member 31 is restrained by the anti-rotation pin 35 as an anti-rotation member disposed at a position eccentric from the center line O of the mounting hole 9, so that the connector of the coolant supply means Alternatively, the cap member 31 can be prevented from rotating together when the tube joint is connected to or removed from the female screw portion 11a, and the cap member 31 can be prevented from loosening or coming off.

  In the second embodiment and the first embodiment as well, the coolant communication hole 10a is formed in the flange portion 3 of the drill body 1 and is opened in the notch surface 3a, and is attached to the shank portion 2. When the connector or tube joint C is connected to the female threaded portion 11a of the cap member 11, 21, or 31, the female threaded portion 10b at the opening of the coolant communication hole 10a is sealed with the sealing screw 16 as described above. However, when the connector or the tube joint C cannot be connected to the female threaded portion 11a of the cap member 11, 21, 31 due to the shape of the tool post for fixing the drill body 1, etc., this coolant communication hole is used. A connector or tube joint C is connected to the female screw portion 10b of 10a, and the female screw portion 11a of the cap members 11, 21, 31 is a sealing screw 1 It may be sealed by.

  In the first and second embodiments, the drill body 1 is fixed to the tool post and the work material is rotated around the center line O to drill the work material. However, the shank portion 2 of the drill main body 1 is attached to the spindle driven to rotate of the machine tool, and the drill main body 1 is fixed while rotating around the center line O, as in the above-described drilling process using a normal drill. Drilling may be performed by feeding the workpiece toward the front end side in the center line O direction. In this case, the female threaded portion 10b of the coolant communication hole 10a is sealed by the sealing screw 16, and the female threaded portion 11a of the cap member 11, 21, 31 is connected to the female threaded portion 11a via a connector or a tube joint C or directly. Coolant is supplied from the machine tool side.

  FIG. 8 shows a third embodiment when the present invention is applied to a boring bar. In the present embodiment, the boring bar main body 41 is formed of a metal material such as steel like the drill main body 1 and has a multi-stage substantially cylindrical shaft shape centering on the center line O, and the rear end portion is the shank portion 42. At the same time, the tip portion is a cutting edge portion 43 having a slightly smaller diameter than the shank portion 42. In the cutting edge portion 43, a single chip discharge groove 44 is formed from the tip of the boring bar main body 41 to the front of the shank portion 42 in parallel to the center line O, and the insert formed at the tip of the chip discharge groove 44. A cutting insert 8 is detachably attached to the mounting seat 7.

  And the attachment hole 9 is formed in the rear-end surface of the shank part 42, The cap member 11 similar to 1st Embodiment is attached to this attachment hole 9 so that attachment or detachment is possible. Further, one coolant hole 10 extends from the outer peripheral portion of the bottom surface of the mounting hole 9 in parallel to the center line O toward the front end side, and a chip discharge groove 44 is formed in the coolant hole 10 at the cutting edge portion 43. It passes through the part which is not made, is bent at the tip of the cutting edge 43 and is opened toward the cutting edge used for cutting of the cutting insert 8. In the present embodiment, the coolant communication hole 10 a is not formed in the coolant hole 10.

  In such a boring bar of the third embodiment, the shank portion 42 of the boring bar main body 41 is attached to the tool post of the machine tool, for example, in the same manner as when drilling is performed in the drill of the first embodiment described above. It is sent to and inserted into a prepared hole formed in advance in a work material that is fixed and rotated around a rotation axis parallel to the center line O, and is used for finishing the prepared hole. Therefore, in the third embodiment, the same effect as that of the first embodiment can be obtained. In the third embodiment, the cap member 21 of the modified example of the first embodiment or the cap member 31 of the second embodiment may be used.

  Further, in the first and second embodiments as well, starting from the third embodiment, the rear end of the notch 12c serving as the opening of the coolant supply passage 12 on the outer peripheral surface of the cap member 11, 21, 31 is provided. An annular groove 11b is formed on the end side to accommodate a sealing member 15 such as an O-ring. The sealing member 15 is interposed between the outer peripheral surface of the cap members 11, 21, 31 and the inner peripheral surface of the mounting hole 9. It is disguised. For this reason, it is possible to reliably prevent coolant leakage from between the mounting hole 9 and the cap members 11, 21, 31, prevent contamination of the drill body 1 and the boring bar body 41, and reduce the consumption of coolant. Can be reduced.

  As described above, in the first and second embodiments, the present invention is applied to a drill, and in the third embodiment, the present invention is applied to a boring bar. Although the case where it applied to the drilling tool to be used was demonstrated, it is also possible to apply this invention to other kinds of cutting tools other than such a drilling tool. However, as described above, cutting with a drilling tool is performed in the hole, so the cutting heat is likely to be trapped and chip clogging is likely to occur, while coolant is supplied from the outside of the tool body of the cutting tool. Since it is difficult to do so, it is more effective to apply the present invention to such a drilling tool.

1 Drill body (tool body)
2, 42 Shank part 9 Mounting hole 10 Coolant hole 11, 21, 31 Cap member 11a Female thread part of cap member 11, 21, 31 12 Coolant supply path 13 Slit 13a End part of slit 13 13b Rear end part 13c of slit 13 Inner peripheral edge of slit 13 14 Mounting screw (rotating stopper)
14a Head of mounting screw 14b Screw shaft portion 14c of mounting screw 14c Engaging portion 15 Seal member 33, 34 Fitting hole 35 Non-rotating pin (anti-rotating member)
41 Boring bar body (tool body)
O Center line of mounting hole 9

Claims (6)

  A coolant supply mechanism in a cutting tool for supplying a coolant to a coolant hole extending from a shank portion at the rear end portion of the tool body of the cutting tool toward the tip portion of the tool body, wherein an attachment hole is formed in the shank portion, The coolant hole is opened at a position eccentric from the center line of the mounting hole, and an outer cylindrical cap member is fitted into the mounting hole, and the coolant supply path and the female are inserted into the cap member. A screw part is formed, the coolant supply path opens into the mounting hole and communicates with the coolant hole, and the female thread part communicates with the coolant supply path and is exposed at the opening of the mounting hole The rear end surface of the member is opened coaxially with the center line, and the cap member is detachably attached to the attachment hole via a rotation preventing member. The detent member may coolant supply mechanism in a cutting tool, characterized in that it is arranged at a position eccentric from the center line to avoid the opening of the coolant hole.   2. The coolant supply mechanism for a cutting tool according to claim 1, wherein the detent member is a mounting screw having a head portion and a screw shaft portion and detachably attaching the cap member to the mounting hole. .   An engagement portion that engages with a work tool is formed on the head portion of the mounting screw, and the cap member has a distal end surface and an outer peripheral surface on the distal end side of the female screw portion. A slit having an inner peripheral end is formed at a position away from the center line while extending to the inner peripheral side, and the tip end portion of the slit is larger than the diameter of the screw shaft portion and smaller than the head portion. The slit has a slit width, the rear end portion of the slit is larger than the head portion, the inner peripheral end side is opened at the bottom surface of the female screw portion, and the mounting screw is the screw shaft portion. Is inserted into the front end portion of the slit and the head portion is inserted into the rear end portion of the slit to be disposed at the inner peripheral end, and the engaging portion is disposed at the inner peripheral end. Exposed from the opening on the bottom of the female thread Coolant supply mechanism in the cutting tool according to claim 2, characterized in that it is engageable with the working tool Te.   The cutting tool according to claim 3, wherein the cap member has a plurality of slits formed at equal intervals in the circumferential direction, and the attachment screw is inserted through each of the slits. Coolant supply mechanism.   A through hole is formed from the bottom surface of the female screw portion to the front end surface of the cap member, and the cap member is detachably attached to the attachment hole by a mounting screw inserted into the through hole, and the 2. The detent pin according to claim 1, wherein the detent member is a detent pin that is fitted into a fitting hole formed at a position eccentric from the center line of the tip surface of the cap member and the bottom surface of the mounting hole. The coolant supply mechanism in the described cutting tool.   A seal member is interposed between the inner peripheral surface of the mounting hole and the outer peripheral surface of the cap member on the rear end side of the coolant supply passage in the mounting hole. The coolant supply mechanism in the cutting tool as described in any one of Claims 1-5.

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